If you're using Sudo, you've probably already discovered that the increased privileges apply only to the first command typed and don't extend to any input or output redirection.

The Linux utility awk can create output redirection for data you want to save and it can use input redirection from commands or respond interactively with users.

In addition to the fairly common forms of input/output redirection the shell recognizes something called process substitution. Although not documented as a form of input/output redirection, its syntax and its effects are similar.

It took me ages to learn bash redirection properly, and I still have to concentrate sometimes to keep my &s and my >s straight. Here's the lowdown in case you, too, have intermittent brain failure on this one. Bash has three standard file descriptors: stdin, stdout and stderr, which refer respectively to input, output and error output.

So considering that compiz++ is now master and my patches haven’t been maintained in a while, a lot of you might be wondering what is going on with input redirection and MPX.

The cpio command is one of the most commonly used Linux back up tools.
The cpio command has two unusual features. Unlike tar , in which the files to back up are typed in as part of the command, cpio reads the files to work with from the standard input (in other words, the screen). This feature means that cpio must be used as part of a multiple command or with a redirection pipe.

Not long ago, there were several discussions on UbuntuForums regarding a malicious command which was deliberately posted in the forums in order to make users damage their system if they typed it in a terminal using root privileges. The command is 'sudo rm -rf /' and means 'use root privileges to recursively remove, without asking for permission, the root directory / and its entire contents.

One of the most powerful features of the Linux command line interface, (and other shells that conform to the POSIX standard) is the ability to pipeline output from one command as the input to another. This is done using the vertical bar or pipe character [ | ].

There are times when you will want to trim some information from the output of a command. This may be because you want to feed that output into another command. Whatever the reason for wanting to manipulate the output, awk is one of many tools available in GNU/Linux to perform this task.